<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>Database Limits and Portability</title>
    <link rel="stylesheet" href="gettingStarted.css" type="text/css" />
    <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
    <link rel="start" href="index.html" title="Getting Started with Berkeley DB" />
    <link rel="up" href="introduction.html" title="Chapter 1. Introduction to Berkeley DB" />
    <link rel="prev" href="accessmethods.html" title="Access Methods" />
    <link rel="next" href="environments.html" title="Environments" />
  </head>
  <body>
    <div xmlns="" class="navheader">
      <div class="libver">
        <p>Library Version 11.2.5.3</p>
      </div>
      <table width="100%" summary="Navigation header">
        <tr>
          <th colspan="3" align="center">Database Limits and Portability</th>
        </tr>
        <tr>
          <td width="20%" align="left"><a accesskey="p" href="accessmethods.html">Prev</a> </td>
          <th width="60%" align="center">Chapter 1. Introduction to Berkeley DB </th>
          <td width="20%" align="right"> <a accesskey="n" href="environments.html">Next</a></td>
        </tr>
      </table>
      <hr />
    </div>
    <div class="sect1" lang="en" xml:lang="en">
      <div class="titlepage">
        <div>
          <div>
            <h2 class="title" style="clear: both"><a id="databaseLimits"></a>Database Limits and Portability</h2>
          </div>
        </div>
      </div>
      <p>
        Berkeley DB provides support for managing everything from very small
        databases that fit entirely in memory, to extremely large databases
        holding millions of records and terabytes of data. DB databases can
        store up to 256 terabytes of data. Individual record keys or record
        data can store up to 4 gigabytes of data.
    </p>
      <p>
        DB's databases store data in a binary format that is portable across
        platforms, even of differing endian-ness. Be aware, however, that
        portability aside, some performance issues can crop up in the event that
        you are using little endian architecture. See <a class="xref" href="btree.html#comparators" title="Setting Comparison Functions">Setting Comparison Functions</a> 
        for more information.
    </p>
      <p>
        Also, DB's databases and data structures are designed for concurrent
        access — they are thread-safe, and they share well across multiple
        processes. That said, in order to allow multiple processes to share
        databases and the cache, DB makes use of mechanisms that do not work
        well on network-shared drives (NFS or Windows networks shares, for
        example). For this reason, you cannot place your DB databases and
        environments on network-mounted drives.
    </p>
    </div>
    <div class="navfooter">
      <hr />
      <table width="100%" summary="Navigation footer">
        <tr>
          <td width="40%" align="left"><a accesskey="p" href="accessmethods.html">Prev</a> </td>
          <td width="20%" align="center">
            <a accesskey="u" href="introduction.html">Up</a>
          </td>
          <td width="40%" align="right"> <a accesskey="n" href="environments.html">Next</a></td>
        </tr>
        <tr>
          <td width="40%" align="left" valign="top">Access Methods </td>
          <td width="20%" align="center">
            <a accesskey="h" href="index.html">Home</a>
          </td>
          <td width="40%" align="right" valign="top"> Environments</td>
        </tr>
      </table>
    </div>
  </body>
</html>
